Cancerous disease modifying antibodies

ABSTRACT

The present invention relates to a method for producing patient cancerous disease modifying antibodies using a novel paradigm of screening. By segregating the anti-cancer antibodies using cancer cell cytotoxicity as an end point, the process makes possible the production of anti-cancer antibodies for therapeutic and diagnostic purposes. The antibodies can be used in aid of staging and diagnosis of a cancer, and can be used to treat primary tumors and tumor metastases. The anti-cancer antibodies can be conjugated to toxins, enzymes, radioactive compounds, and hematogenous cells.

REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 10/762,129,filed Jan. 20, 2004, which is a continuation-in-part of application Ser.No. 10/743,451, filed on Dec. 19, 2003, now abandoned, which is acontinuation of application Ser. No. 10/348,231, filed Jan. 21, 2003,now U.S. Pat. No. 7,009,040, issued on Mar. 7, 2006, the contents ofwhich are herein incorporated by reference.

FIELD OF THE INVENTION

This invention relates to the isolation and production of cancerousdisease modifying antibodies (CDMAB) and to the use of these CDMAB intherapeutic and diagnostic processes, optionally in combination with oneor more chemotherapeutic agents. The invention further relates tobinding assays which utilize the CDMAB of the instant invention.

BACKGROUND OF THE INVENTION

Each individual who presents with cancer is unique and has a cancer thatis as different from other cancers as that person's identity. Despitethis, current therapy treats all patients with the same type of cancer,at the same stage, in the same way. At least 30 percent of thesepatients will fail the first line of therapy, thus leading to furtherrounds of treatment and the increased probability of treatment failure,metastases, and ultimately, death. A superior approach to treatmentwould be the customization of therapy for the particular individual. Theonly current therapy that lends itself to customization is surgery.Chemotherapy and radiation treatment cannot be tailored to the patient,and surgery by itself, in most cases is inadequate for producing cures.

With the advent of monoclonal antibodies, the possibility of developingmethods for customized therapy became more realistic since each antibodycan be directed to a single epitope. Furthermore, it is possible toproduce a combination of antibodies that are directed to theconstellation of epitopes that uniquely define a particular individual'stumor.

Having recognized that a significant difference between cancerous andnormal cells is that cancerous cells contain antigens that are specificto transformed cells, the scientific community has long held thatmonoclonal antibodies can be designed to specifically target transformedcells by binding specifically to these cancer antigens; thus giving riseto the belief that monoclonal antibodies can serve as “Magic Bullets” toeliminate cancer cells.

Monoclonal antibodies isolated in accordance with the teachings of theinstantly disclosed invention have been shown to modify the cancerousdisease process in a manner which is beneficial to the patient, forexample by reducing the tumor burden, and will variously be referred toherein as cancerous disease modifying antibodies (CDMAB) or“anti-cancer” antibodies.

At the present time, the cancer patient usually has few options oftreatment. The regimented approach to cancer therapy has producedimprovements in global survival and morbidity rates. However, to theparticular individual, these improved statistics do not necessarilycorrelate with an improvement in their personal situation.

Thus, if a methodology was put forth which enabled the practitioner totreat each tumor independently of other patients in the same cohort,this would permit the unique approach of tailoring therapy to just thatone person. Such a course of therapy would, ideally, increase the rateof cures, and produce better outcomes, thereby satisfying a long-feltneed.

Historically, the use of polyclonal antibodies has been used withlimited success in the treatment of human cancers. Lymphomas andleukemias have been treated with human plasma, but there were fewprolonged remissions or responses. Furthermore, there was a lack ofreproducibility and no additional benefit compared to chemotherapy.Solid tumors such as breast cancers, melanomas and renal cell carcinomashave also been treated with human blood, chimpanzee serum, human plasmaand horse serum with correspondingly unpredictable and ineffectiveresults.

There have been many clinical trials of monoclonal antibodies for solidtumors. In the 1980s there were at least 4 clinical trials for humanbreast cancer which produced only 1 responder from at least 47 patientsusing antibodies against specific antigens or based on tissueselectivity. It was not until 1998 that there was a successful clinicaltrial using a humanized anti-Her2 antibody in combination withcisplatin. In this trial 37 patients were accessed for responses ofwhich about a quarter had a partial response rate and another half hadminor or stable disease progression.

The clinical trials investigating colorectal cancer involve antibodiesagainst both glycoprotein and glycolipid targets. Antibodies such as17-1A, which has some specificity for adenocarcinomas, had undergonePhase 2 clinical trials in over 60 patients with only 1 patient having apartial response. In other trials, use of 17-1A produced only 1 completeresponse and 2 minor responses among 52 patients in protocols usingadditional cyclophosphamide. Other trials involving 17-1A yieldedresults that were similar. The use of a humanized murine monoclonalantibody initially approved for imaging also did not produce tumorregression. To date there has not been an antibody that has beeneffective for colorectal cancer. Likewise there have been equally poorresults for lung, brain, ovarian, pancreatic, prostate, and stomachcancers. There has been some limited success in the use of an anti-GD3monoclonal antibody for melanoma. Thus, it can be seen that despitesuccessful small animal studies that are a prerequisite for humanclinical trials, the antibodies that have been tested thus far, havebeen for the most part, ineffective.

Prior Patents

U.S. Pat. No. 5,750,102 discloses a process wherein cells from apatient's tumor are transfected with MHC genes which may be cloned fromcells or tissue from the patient. These transfected cells are then usedto vaccinate the patient.

U.S. Pat. No. 4,861,581 discloses a process comprising the steps ofobtaining monoclonal antibodies that are specific to an internalcellular component of neoplastic and normal cells of the mammal but notto external components, labeling the monoclonal antibody, contacting thelabeled antibody with tissue of a mammal that has received therapy tokill neoplastic cells, and determining the effectiveness of therapy bymeasuring the binding of the labeled antibody to the internal cellularcomponent of the degenerating neoplastic cells. In preparing antibodiesdirected to human intracellular antigens, the patentee recognizes thatmalignant cells represent a convenient source of such antigens.

U.S. Pat. No. 5,171,665 provides a novel antibody and method for itsproduction. Specifically, the patent teaches formation of a monoclonalantibody which has the property of binding strongly to a protein antigenassociated with human tumors, e.g. those of the colon and lung, whilebinding to normal cells to a much lesser degree.

U.S. Pat. No. 5,484,596 provides a method of cancer therapy comprisingsurgically removing tumor tissue from a human cancer patient, treatingthe tumor tissue to obtain tumor cells, irradiating the tumor cells tobe viable but non-tumorigenic, and using these cells to prepare avaccine for the patient capable of inhibiting recurrence of the primarytumor while simultaneously inhibiting metastases. The patent teaches thedevelopment of monoclonal antibodies which are reactive with surfaceantigens of tumor cells. As set forth at col. 4, lines 45 et seq., thepatentees utilize autochthonous tumor cells in the development ofmonoclonal antibodies expressing active specific immunotherapy in humanneoplasia.

U.S. Pat. No. 5,693,763 teaches a glycoprotein antigen characteristic ofhuman carcinomas is not dependent upon the epithelial tissue of origin.

U.S. Pat. No. 5,783,186 is drawn to anti-Her2 antibodies which induceapoptosis in Her2 expressing cells, hybridoma cell lines producing theantibodies, methods of treating cancer using the antibodies andpharmaceutical compositions including said antibodies.

U.S. Pat. No. 5,849,876 describes new hybridoma cell lines for theproduction of monoclonal antibodies to mucin antigens purified fromtumor and non-tumor tissue sources.

U.S. Pat. No. 5,869,268 is drawn to a method for generating a humanlymphocyte producing an antibody specific to a desired antigen, a methodfor producing a monoclonal antibody, as well as monoclonal antibodiesproduced by the method. The patent is particularly drawn to theproduction of an anti-HD human monoclonal antibody useful for thediagnosis and treatment of cancers.

U.S. Pat. No. 5,869,045 relates to antibodies, antibody fragments,antibody conjugates and single chain immunotoxins reactive with humancarcinoma cells. The mechanism by which these antibodies function istwo-fold, in that the molecules are reactive with cell membrane antigenspresent on the surface of human carcinomas, and further in that theantibodies have the ability to internalize within the carcinoma cells,subsequent to binding, making them especially useful for formingantibody-drug and antibody-toxin conjugates. In their unmodified formthe antibodies also manifest cytotoxic properties at specificconcentrations.

U.S. Pat. No. 5,780,033 discloses the use of autoantibodies for tumortherapy and prophylaxis. However, this antibody is an anti-nuclearautoantibody from an aged mammal. In this case, the autoantibody is saidto be one type of natural antibody found in the immune system. Becausethe autoantibody comes from “an aged mammal”, there is no requirementthat the autoantibody actually comes from the patient being treated. Inaddition the patent discloses natural and monoclonal anti-nuclearautoantibody from an aged mammal, and a hybridoma cell line producing amonoclonal anti-nuclear autoantibody.

SUMMARY OF THE INVENTION

The instant inventors have previously been awarded U.S. Pat. No.6,180,357, entitled “Individualized Patient Specific Anti-CancerAntibodies” directed to a process for selecting individually customizedanti-cancer antibodies which are useful in treating a cancerous disease.For the purpose of this document, the terms “antibody” and “monoclonalantibody” (mAb) may be used interchangeably and refer to intactimmunoglobulins produced by hybridomas (e.g. murine or human),immunoconjugates and, as appropriate, immunoglobulin fragments andrecombinant proteins derived from immunoglobulins, such as chimeric andhumanized immunoglobulins, F(ab′) and F(ab′)₂ fragments, single-chainantibodies, recombinant immunoglobulin variable regions (Fv)s, fusionproteins etc. It is well recognized in the art that some amino acidsequence can be varied in a polypeptide without significant effect onthe structure or function of the protein. In the molecular rearrangementof antibodies, modifications in the nucleic or amino acid sequence ofthe backbone region can generally be tolerated. These include, but arenot limited to, substitutions (preferred are conservativesubstitutions), deletions or additions. Furthermore, it is within thepurview of this invention to conjugate standard chemotherapeuticmodalities, e.g. radionuclides, with the CDMAB of the instant invention,thereby focusing the use of said chemotherapeutics. The CDMAB can alsobe conjugated to toxins, cytotoxic moieties, enzymes e.g. biotinconjugated enzymes, or hematogenous cells.

The prospect of individualized anti-cancer treatment will bring about achange in the way a patient is managed. A likely clinical scenario isthat a tumor sample is obtained at the time of presentation, and banked.From this sample, the tumor can be typed from a panel of pre-existingcancerous disease modifying antibodies. The patient will beconventionally staged but the available antibodies can be of use infurther staging the patient. The patient can be treated immediately withthe existing antibodies and/or a panel of antibodies specific to thetumor can be produced either using the methods outlined herein orthrough the use of phage display libraries in conjunction with thescreening methods herein disclosed. All the antibodies generated will beadded to the library of anti-cancer antibodies since there is apossibility that other tumors can bear some of the same epitopes as theone that is being treated. The antibodies produced according to thismethod may be useful to treat cancerous disease in any number ofpatients who have cancers that bind to these antibodies.

Using substantially the process of U.S. Pat. No. 6,180,370, the mousemonoclonal antibody 11BD-2E11-2 was obtained following immunization ofmice with cells from a patient's breast tumor biopsy. Within the contextof this application, anti-cancer antibodies having either cell-killing(cytotoxic) or cell-growth inhibiting (cytostatic) properties willhereafter be referred to as cytotoxic. This antibody can be used in aidof staging and diagnosis of a cancer, and can be used to treat tumormetastases. The 11BD-2E11-2 antigen was expressed on the cell surface ofa broad range of human cell lines from different tissue origins. Thebreast cancer cell line MCF-7 and ovarian cancer cell line OVCAR-3 werethe only two cancer cell lines tested that were susceptible to thecytotoxic effects of 11BD-2E11-2 as described in Ser. No. 10/348,231.

The in vitro effects of 11BD-2E11-2 against breast and ovarian cancercells were extended by establishing its anti-tumor activity in vivo. Invivo models of human cancer were established by implanting the MCF-7breast cancer cells or OVCAR-3 ovarian cancer cells into severe combinedimmunodeficient (SCID) mice, as they are incapable of rejecting thehuman tumor cells due to a lack of certain immune cells. The effects ofdrugs tested in these kinds of pre-clinical xenograft tumor models areconsidered valid predictors of therapeutic efficacy. Cancer xenograftsin mice grow as solid tumors developing parenchyma, stroma, centralnecrosis and neo-vasculature in the same manner as naturally occurringcancers. The mammary cancer cell line MCF-7 and the ovarian cancer cellline OVCAR-3 have been evaluated in SCID mice. The successfulengraftment of both the MCF-7 and OVCAR-3 tumors and the sensitivity ofthe tumors to standard chemotherapeutic agents have characterized themas suitable models of human cancer for drug testing. The MCF-7 parentalcell line and its variants and the OVCAR-3 cell line have been usedsuccessfully in xenograft tumor models to evaluate a wide range oftherapeutic agents that have been used as clinical chemotherapeuticagents.

11BD-2E11-2 prevented tumor growth and reduced tumor burden in apreventative in vivo model of human breast cancer. Monitoring continuedpast 280 days post-treatment. 40 percent of the 11BD-2E11-2 treatmentgroup was still alive at over 7.5 months post-implantation. Conversely,the isotype control group had 100 percent mortality after 6.5 monthspost-treatment. At day 51 (soon after last treatment), the mean tumorvolume in the 11BD-2E11-2 treated group was 20% of the isotype control(p=0.0098). Therefore 11BD-2E11-2 enhanced survival and decreased thetumor burden compared to the control-treated groups in awell-established model of human breast cancer.

In addition to the beneficial effects in a model of human breast cancer,11BD-2E11-2 treatment also had anti-tumor activity against OVCAR-3 cellsin an ovarian cancer model. Body weight was used a surrogate measure oftumor progression in this model. At day 80 post-implantation (16 daysafter the end of treatment) the mice in the treated group had 87.6percent the mean body weight of the control group (p=0.015). Thus,11BD-2E11-2 treatment was efficacious as it delayed tumor progressioncompared to the buffer control treated group in a well-established modelof human ovarian cancer. The anti-tumor activities of 11BD-2E11-2, inseveral different cancer models, make it an attractive anti-cancertherapeutic agent.

In all, this invention teaches the use of the 11BD-2E11-2 antigen as atarget for a therapeutic agent, that when administered can reduce thetumor burden of a cancer expressing the antigen in a mammal, and canalso lead to a prolonged survival of the treated mammal. This inventionalso teaches the use of CDMAB (11BD-2E11-2), and its derivatives, totarget its antigen to reduce the tumor burden of a cancer expressing theantigen in a mammal, and to prolong the survival of a mammal bearingtumors that express this antigen.

If a patient is refractory to the initial course of therapy ormetastases develop, the process of generating specific antibodies to thetumor can be repeated for re-treatment. Furthermore, the anti-cancerantibodies can be conjugated to red blood cells obtained from thatpatient and re-infused for treatment of metastases. There have been feweffective treatments for metastatic cancer and metastases usuallyportend a poor outcome resulting in death. However, metastatic cancersare usually well vascularized and the delivery of anti-cancer antibodiesby red blood cells can have the effect of concentrating the antibodiesat the site of the tumor. Even prior to metastases, most cancer cellsare dependent on the host's blood supply for their survival and ananti-cancer antibody conjugated to red blood cells can be effectiveagainst in situ tumors as well. Alternatively, the antibodies may beconjugated to other hematogenous cells, e.g. lymphocytes, macrophages,monocytes, natural killer cells, etc.

There are five classes of antibodies and each is associated with afunction that is conferred by its heavy chain. It is generally thoughtthat cancer cell killing by naked antibodies are mediated either throughantibody-dependent cell-mediated cytotoxicity (ADCC) orcomplement-dependent cytotoxicity (CDC). For example murine IgM andIgG2a antibodies can activate human complement by binding the C-1component of the complement system thereby activating the classicalpathway of complement activation which can lead to tumor lysis. Forhuman antibodies, the most effective complement activating antibodiesare generally IgM and IgG1. Murine antibodies of the IgG2a and IgG3isotype are effective at recruiting cytotoxic cells that have Fcreceptors which will lead to cell killing by monocytes, macrophages,granulocytes and certain lymphocytes. Human antibodies of both the IgG1and IgG3 isotype mediate ADCC.

Another possible mechanism of antibody mediated cancer killing may bethrough the use of antibodies that function to catalyze the hydrolysisof various chemical bonds in the cell membrane and its associatedglycoproteins or glycolipids, so-called catalytic antibodies.

There are two additional mechanisms of antibody mediated cancer cellkilling which are more widely accepted. The first is the use ofantibodies as a vaccine to induce the body to produce an immune responseagainst the putative antigen that resides on the cancer cell. The secondis the use of antibodies to target growth receptors and interfere withtheir function or to down regulate that receptor so that effectively itsfunction is lost.

The clinical utility of a cancer drug is based on the benefit of thedrug under an acceptable risk profile to the patient. In cancer therapysurvival has generally been the most sought after benefit, however thereare a number of other well-recognized benefits in addition to prolonginglife. These other benefits, where treatment does not adversely affectsurvival, include symptom palliation, protection against adverse events,prolongation in time to recurrence or disease-free survival, andprolongation in time to progression. These criteria are generallyaccepted and regulatory bodies such as the U.S. Food and DrugAdministration (F.D.A.) approve drugs that produce these benefits(Hirschfeld et al. Critical Reviews in Oncology/Hematolgy 42:137-1432002). In addition to these criteria it is well-recognized that thereare other endpoints that may presage these types of benefits. In part,the accelerated approval process granted by the U.S. F.D.A. acknowledgesthat there are surrogates that will likely predict patient benefit. Asof year-end (2003), there has been sixteen drugs approved under thisprocess, and of these, four have gone on to full approval, i.e.,follow-up studies have demonstrated direct patient benefit as predictedby surrogate endpoints. One important endpoint for determining drugeffects in solid tumors is the assessment of tumor burden by measuringresponse to treatment (Therasse et al. Journal of the National CancerInstitute 92(3):205-216 2000). The clinical criteria (RECIST criteria)for such evaluation have been promulgated by Response EvaluationCriteria in Solid Tumors Working Group, a group of international expertsin cancer. Drugs with a demonstrated effect on tumor burden, as shown byobjective responses according to RECIST criteria, in comparison to theappropriate control group tend to, ultimately, produce direct patientbenefit. In the pre-clinical setting tumor burden is generally morestraightforward to assess and document. In that pre-clinical studies canbe translated to the clinical setting, drugs that produce prolongedsurvival in pre-clinical models have the greatest anticipated clinicalutility. Analogous to producing positive responses to clinicaltreatment, drugs that reduce tumor burden in the pre-clinical settingmay also have significant direct impact on the disease. Althoughprolongation of survival is the most sought after clinical outcome fromcancer drug treatment, there are other benefits that have clinicalutility and it is clear that tumor burden reduction can also lead todirect benefits and have clinical impact (Eckhardt et al. DevelopmentalTherapeutics: Successes and Failures of Clinical Trial Designs ofTargeted Compounds; ASCO Educational Book, 39^(th) Annual Meeting, 2003,pages 209-219).

Accordingly, it is an objective of the invention to utilize a method forproducing CDMAB from cells derived from a particular individual whichare cytotoxic with respect to cancer cells while simultaneously beingrelatively non-toxic to non-cancerous cells, in order to isolatehybridoma cell lines and the corresponding isolated monoclonalantibodies and antigen binding fragments thereof for which saidhybridoma cell lines are encoded.

It is an additional objective of the invention to teach CDMAB andantigen binding fragments thereof.

It is a further objective of the instant invention to produce CDMABwhose cytotoxicity is mediated through ADCC.

It is yet an additional objective of the instant invention to produceCDMAB whose cytotoxicity is mediated through CDC.

It is still a further objective of the instant invention to produceCDMAB whose cytotoxicity is a function of their ability to catalyzehydrolysis of cellular chemical bonds.

A still further objective of the instant invention is to produce CDMABwhich are useful in a binding assay for the diagnosis, prognosis, andmonitoring of cancer.

Other objects and advantages of this invention will become apparent fromthe following description wherein are set forth, by way of illustrationand example, certain embodiments of this invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1. Effect of 11BD-2E11-2 on tumor growth in a preventative MCF-7breast cancer model. The dashed line indicates the period during whichthe antibody was administered. Data points represent the mean +/− SEM.

FIG. 2. Survival of tumor-bearing mice after treatment with 11BD-2E11-2or isotype control antibody in a preventative MCF-7 xenograft study.Mice were monitored for survival for longer than 230 dayspost-treatment.

FIG. 3. Effect of 11BD-2E11-2 on mean body weight in a preventativeOVCAR-3 ovarian cancer model. The solid line indicates the period duringwhich the antibody was administered. Data points represent the mean +/−SEM.

FIG. 4. Survival of tumor-bearing mice after treatment with 11BD-2E11-2or buffer control antibody in a preventative OVCAR-3 study. Mice weremonitored for survival for approximately 60 days post-treatment.

DETAILED DESCRIPTION OF THE INVENTION EXAMPLE 1

The hybridoma cell line 11BD-2E11-2 was deposited, in accordance withthe Budapest Treaty, with the American Type Culture Collection, 10801University Blvd., Manassas, Va. 20110-2209 on Nov. 11, 2003, underAccession Number PTA-5643. In accordance with 37 CFR 1.808, thedepositors assure that all restrictions imposed on the availability tothe public of the deposited materials will be irrevocably removed uponthe granting of a patent.

11BD-2E11-2 monoclonal antibody was produced by culturing the hybridomasin CL-1000 flasks (BD Biosciences, Oakville, ON) with collections andreseeding occurring twice/week and with purification according tostandard antibody purification procedures with Protein G Sepharose 4Fast Flow (Amersham Biosciences, Baie d'Urfé, QC).

In Vivo MCF-7 Preventative Survival Tumor Experiment

With reference to FIGS. 1 and 2, 4 to 8 week old female SCID mice wereimplanted with 5 million MCF-7 human breast cancer cells in 100microlitres saline injected subcutaneously in the scruff of the neck.The mice were randomly divided into 2 treatment groups of 11-13 mice. Onthe day after implantation, 20 mg/kg of either 11BD-2E11-2 test antibodyor isotype control antibody (known not to bind MCF-7 or OVCAR-3 cells)was administered intraperitoneally at a volume of 300 microliters afterdilution from the stock concentration with a diluent that contained 2.7mM KCl, 1 mM KH₂PO₄, 137 mM NaCl and 20 mM Na₂HPO₄. The antibodies werethen administered once per week for a period of 7 weeks in the samefashion. Tumor growth was measured about every seventh day with calipersfor up to 8 weeks or until individual animals reached the CanadianCouncil for Animal Care (CCAC) end-points. Body weights of the animalswere recorded for the duration of the study. At the end of the study allanimals were euthanised according to CCAC guidelines.

11BD-2E11-2 significantly reduced the tumor burden in treated mice incomparison to controls (FIG. 1). After treatment (day 51), 11BD-2E11-2prevented tumor growth by 80 percent (p=0.0098) in comparison to isotypecontrol antibody treated mice. There was also a post-treatment survivalbenefit (FIG. 2) associated with 11BD-2E11-2 administration. The isotypecontrol antibody treated group reached 100 percent mortality by day 197post-treatment while 40 percent of the 11BD-2E11-2 treated group werestill alive at day 233. In summary, 11BD-2E11-2 increased survival anddecreased tumor burden in a well-established model of human breastcancer (Blakey et al. Clinical Cancer Research 8:1974-1983 2002; Klementet al. Clinical Cancer Research 8:221-232 2002; Waud et al. Relevance ofTumor Models for Anticancer Drug Development, Fiebig and Burger, eds.54:305-315 1999; Karpanen et al. Cancer Research 61:1786-1790 2001).

EXAMPLE 2 In Vivo OVCAR-3 Preventative Tumor Experiments

With reference to the data shown in FIGS. 3 and 4, 4 to 8 week old,female SCID mice were implanted with 5 million OVCAR-3 human ovariancancer cells in 1000 microliters saline injected intraperitoneally. Themice were randomly divided into 2 treatment groups of 10. On the dayafter implantation, 20 mg/kg of 11BD-2E11-2 test antibody or buffercontrol antibody was administered intraperitoneally at a volume of 300microliters after dilution from the stock concentration with a diluentthat contained 2.7 mM KCl, 1 mM KH₂PO₄, 137 mM NaCl and 20 mM Na₂HPO₄.The antibodies were then administered once per week for a period of 9weeks in the same fashion. Body weights of the animals were recorded forthe duration of the study. At the end of the study all animals wereeuthanised according to CCAC guidelines.

In the OVCAR-3 ovarian cancer xenograft model, increasing body weightcan be used as a surrogate indicator of disease progression since thisreflects the accumulation of ascites from increased tumor burden (FIG.3). At day 80 post-implantation (16 days after the end of treatment),11BD-2E11-2 administration prevented body weight gain by 12.4 percent(p=0.015) compared to the buffer control group. Mice were monitoredpost-treatment for survival (FIG. 4). By day 87, the buffer controlgroup had reached 90 percent mortality while the 11BD-2E11-2 treatedgroup still had 80 percent survival. The 11BD-2E11-2 treated group didnot reach 90 percent mortality until day 125. In summary, 11BD-2E11-2antibody treatment reduced tumor burden, delayed disease progression andenhanced survival in comparison to a buffer control antibody in awell-recognized model of human ovarian cancer. Therefore treatment with11BD-2E11-2 significantly decreased the tumor burden of establishedtumors in two well-recognized models of human cancer disease (breast andovarian cancers) suggesting pharmacologic and pharmaceutical benefits ofthis antibody for therapy in other mammals, including man (Smith et al.The Prostate 48:47-53 2001; Olson et al. International Journal of Cancer98:923-929 2002; Guilbaud et al. Clinical Cancer Research 7:2573-25802001; Von Gruenigen et al. International Journal of Gynecologic Cancer9:365-372 1999; Guichard et al. Clinical Cancer Research 7:3222-32282001; Xiao et al. Protein Expression and Purification 19:12-21 2000).

All patents and publications mentioned in this specification areindicative of the levels of those skilled in the art to which theinvention pertains. All patents and publications are herein incorporatedby reference to the same extent as if each individual publication wasspecifically and individually indicated to be incorporated by reference.

It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementof parts herein described and shown. It will be apparent to thoseskilled in the art that various changes may be made without departingfrom the scope of the invention and the invention is not to beconsidered limited to what is shown and described in the specification.One skilled in the art will readily appreciate that the presentinvention is well adapted to carry out the objects and obtain the endsand advantages mentioned, as well as those inherent therein. Anyoligonucleotides, peptides, polypeptides, biologically relatedcompounds, methods, procedures and techniques described herein arepresently representative of the preferred embodiments, are intended tobe exemplary and are not intended as limitations on the scope. Changestherein and other uses will occur to those skilled in the art which areencompassed within the spirit of the invention and are defined by thescope of the appended claims. Although the invention has been describedin connection with specific preferred embodiments, it should beunderstood that the invention as claimed should not be unduly limited tosuch specific embodiments. Indeed, various modifications of thedescribed modes for carrying out the invention which are obvious tothose skilled in the art are intended to be within the scope of thefollowing claims.

1. A method of extending survival and/or delaying disease progression bytreating a human tumor in a mammal, wherein said tumor expresses anantigen which specifically binds to a monoclonal antibody or antigenbinding fragment thereof which has the identifying characteristics of amonoclonal antibody encoded by a clone deposited with the ATCC asaccession number PTA-5643 comprising administering to said mammal saidmonoclonal antibody in an amount effective to reduce said mammal's tumorburden, whereby disease progression is delayed and/or survival isextended.
 2. The method of claim 1 wherein said antibody is conjugatedto a cytotoxic moiety.
 3. The method of claim 2 wherein said cytotoxicmoiety is a radioactive isotope.
 4. The method of claim 1 wherein saidantibody activates complement.
 5. The method of claim 1 wherein saidantibody mediates antibody dependent cellular cytotoxicity.
 6. Themethod of claim 1 wherein said antibody is a murine antibody.
 7. Themethod of claim 1 wherein said antibody is a humanized antibody.
 8. Themethod of claim 1 wherein said antibody is a chimerized antibody.
 9. Anisolated monoclonal antibody or antigen binding fragments thereofencoded by the clone deposited with the ATCC as PTA-5643.
 10. Theisolated antibody or antigen binding fragments of claim 9, wherein saidisolated antibody or antigen binding fragments thereof is humanized. 11.The isolated antibody or antigen binding fragments of claim 9 conjugatedwith a member selected from the group consisting of cytotoxic moieties,enzymes, radioactive compounds, and hematogenous cells.
 12. The isolatedantibody or antigen binding fragments of claim 9, wherein said isolatedantibody or antigen binding fragments thereof is a chimerized antibody.13. The isolated antibody or antigen binding fragments of claim 9,wherein said isolated antibody or antigen binding fragments thereof is amurine antibody.
 14. The isolated clone deposited with the ATCC asPTA-5643.
 15. The method of claim 1 wherein said tumor is a breasttumor.
 16. The method of claim 1 wherein said tumor is an ovarian tumor.